Add ViewHolderCache

TellH · Jan 22, 2017 · c773605 · c773605
1 parent 8e66e25
commit c773605
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Showing 7 changed files with 97 additions and 73 deletions.
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
diff --git a/app/src/main/java/tellh/com/recyclerstickyheaderview/MainActivity.java b/app/src/main/java/tellh/com/recyclerstickyheaderview/MainActivity.java
@@ -16,8 +16,6 @@
 
 public class MainActivity extends AppCompatActivity {
     private RecyclerView rv;
-    private LinearLayoutManager linearLayoutManager;
-    private StickyHeaderView stickyHeaderView;
     private StickyHeaderViewAdapter adapter;
 
     @Override
@@ -58,8 +56,7 @@ public int compare(User o1, User o2) {
 
     private void initView() {
         rv = (RecyclerView) findViewById(R.id.recyclerView);
-        stickyHeaderView = (StickyHeaderView) findViewById(R.id.stickyHeaderView);
-        linearLayoutManager = new LinearLayoutManager(this);
+        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
         rv.setLayoutManager(linearLayoutManager);
     }
 
@@ -73,11 +70,10 @@ public boolean onCreateOptionsMenu(Menu menu) {
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.action_add_view:
-//                stickyHeaderView.clearHeaderView();
-//                stickyHeaderView.updateHeaderView(R.layout.header, entity, position);
-                break;
-            case R.id.action_remove_view:
-                stickyHeaderView.clearHeaderView();
+                User user = new User("Sticky View", 123, "https://avatars.githubusercontent.com/u/15800681?v=3");
+                user.setShouldSticky(true);
+                adapter.getDisplayList().add(3, user);
+                adapter.notifyItemInserted(3);
                 break;
             default:
                 break;

diff --git a/app/src/main/java/tellh/com/recyclerstickyheaderview/StickyHeaderView.java b/app/src/main/java/tellh/com/recyclerstickyheaderview/StickyHeaderView.java
@@ -5,6 +5,7 @@
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
+import android.util.LruCache;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -26,6 +27,7 @@ public class StickyHeaderView extends FrameLayout {
     private StickyHeaderViewAdapter adapter;
     private LinearLayoutManager layoutManager;
     private Stack<Integer> stickyHeaderPositionStack = new Stack<>();
+    private LruCache<Integer, RecyclerView.ViewHolder> mViewHolderCache;
 
     public StickyHeaderView(Context context) {
         super(context);
@@ -53,54 +55,61 @@ private void initView() {
         mHeaderContainer.setLayoutParams(
                 new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
         addView(mHeaderContainer);
-        mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
-            @Override
-            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
-                super.onScrollStateChanged(recyclerView, newState);
-                if (mHeaderHeight == -1 || mHeaderHeight == 0 || adapter == null || layoutManager == null) {
-                    mHeaderHeight = mHeaderContainer.getHeight();
-                    adapter = (StickyHeaderViewAdapter) mRecyclerView.getAdapter();
-                    layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
-                    if (adapter != null)
-                        stickyHeaderPositionStack.push(findFirstVisibleStickyHeaderPosition(adapter.displayList, 0));
-                }
-            }
-
-            @Override
-            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
-                super.onScrolled(recyclerView, dx, dy);
-                if (mHeaderHeight == -1 || adapter == null || layoutManager == null)
-                    return;
-                List<DataBean> displayList = adapter.getDisplayList();
-                int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
-                int firstVisibleStickyHeaderPosition = findFirstVisibleStickyHeaderPosition(displayList, firstVisibleItemPosition);
-                int currentStickyHeaderPosition = stickyHeaderPositionStack.peek();
-                if (firstVisibleStickyHeaderPosition - firstVisibleItemPosition > 1) {
-                    return;
-                }
-                View firstVisibleStickyHeader = layoutManager.findViewByPosition(firstVisibleStickyHeaderPosition);
-                if (firstVisibleStickyHeader == null)
-                    return;
-                int headerTop = firstVisibleStickyHeader.getTop();
-                if (headerTop > 0 && headerTop <= mHeaderHeight) {
-                    mHeaderContainer.setY(-(mHeaderHeight - headerTop));
-                    if (firstVisibleStickyHeaderPosition == currentStickyHeaderPosition) {
-                        stickyHeaderPositionStack.pop();
-                        if (!stickyHeaderPositionStack.isEmpty())
-                            updateHeaderView(stickyHeaderPositionStack.peek());
+        mRecyclerView.addOnScrollListener(
+                new RecyclerView.OnScrollListener() {
+                    @Override
+                    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
+                        super.onScrollStateChanged(recyclerView, newState);
+                        if (mHeaderHeight == -1 || mHeaderHeight == 0 || adapter == null || layoutManager == null) {
+                            mHeaderHeight = mHeaderContainer.getHeight();
+                            adapter = (StickyHeaderViewAdapter) mRecyclerView.getAdapter();
+                            layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
+                            if (adapter != null) {
+                                mViewHolderCache = new LruCache<>(adapter.getItemCount() / 3);
+                            }
+                        }
                     }
-                } else if (headerTop <= 0) {
-                    mHeaderContainer.setY(0);
-                    updateHeaderView(firstVisibleItemPosition);
-                }
 
-                // Cache the StickyHeader position.
-                if (firstVisibleStickyHeaderPosition > currentStickyHeaderPosition)
-                    stickyHeaderPositionStack.push(firstVisibleStickyHeaderPosition);
-                else if (firstVisibleStickyHeaderPosition < currentStickyHeaderPosition)
-                    stickyHeaderPositionStack.pop();
+                    @Override
+                    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
+                        super.onScrolled(recyclerView, dx, dy);
+                        if (mHeaderHeight == -1 || adapter == null || layoutManager == null)
+                            return;
+                        List<DataBean> displayList = adapter.getDisplayList();
+                        if (stickyHeaderPositionStack.isEmpty())
+                            stickyHeaderPositionStack.push(findFirstVisibleStickyHeaderPosition(adapter.displayList, 0));
+                        int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
+                        int firstVisibleStickyHeaderPosition = findFirstVisibleStickyHeaderPosition(displayList, firstVisibleItemPosition);
+                        int currentStickyHeaderPosition = stickyHeaderPositionStack.peek();
+                        if (firstVisibleStickyHeaderPosition - firstVisibleItemPosition > 1) {
+                            return;
+                        }
+                        // 如果两个连续两个都是StickyView, 取下面那个View
+                        if (displayList.get(firstVisibleStickyHeaderPosition + 1).shouldSticky())
+                            firstVisibleStickyHeaderPosition++;
+                        View firstVisibleStickyHeader = layoutManager.findViewByPosition(firstVisibleStickyHeaderPosition);
+                        if (firstVisibleStickyHeader == null)
+                            return;
+                        int headerTop = firstVisibleStickyHeader.getTop();
+                        if (headerTop > 0 && headerTop <= mHeaderHeight) {
+                            mHeaderContainer.setY(-(mHeaderHeight - headerTop));
+                            if (firstVisibleStickyHeaderPosition == currentStickyHeaderPosition) {
+                                stickyHeaderPositionStack.pop();
+                                if (!stickyHeaderPositionStack.isEmpty())
+                                    updateHeaderView(stickyHeaderPositionStack.peek());
+                            }
+                        } else if (headerTop <= 0) {
+                            mHeaderContainer.setY(0);
+                            updateHeaderView(firstVisibleItemPosition);
+                        }
+
+                        // Cache the StickyHeader position.
+                        if (firstVisibleStickyHeaderPosition > currentStickyHeaderPosition)
+                            stickyHeaderPositionStack.push(firstVisibleStickyHeaderPosition);
+                        else if (firstVisibleStickyHeaderPosition < currentStickyHeaderPosition)
+                            stickyHeaderPositionStack.pop();
+                    }
                 }
-            }
 
         );
 
@@ -116,19 +125,24 @@ private int findFirstVisibleStickyHeaderPosition(List<DataBean> displayList, int
         return i;
     }
 
-    public void updateHeaderView(int position) {
+    private void updateHeaderView(int position) {
         DataBean entity = adapter.getDisplayList().get(position);
         int layoutId = entity.getItemLayoutId(adapter);
         clearHeaderView();
-        View v = LayoutInflater.from(mHeaderContainer.getContext())
-                .inflate(layoutId, mHeaderContainer, false);
-        mHeaderContainer.addView(v);
-        mHeaderHeight = mHeaderContainer.getHeight();
+        RecyclerView.ViewHolder viewHolder = mViewHolderCache.get(layoutId);
         ViewBinder headerViewBinder = adapter.getViewBinder(layoutId);
-        headerViewBinder.bindView(adapter, headerViewBinder.provideViewHolder(v), position, entity);
+        if (viewHolder == null) {
+            View v = LayoutInflater.from(mHeaderContainer.getContext())
+                    .inflate(layoutId, mHeaderContainer, false);
+            viewHolder = headerViewBinder.provideViewHolder(v);
+            mViewHolderCache.put(layoutId, viewHolder);
+        }
+        mHeaderContainer.addView(viewHolder.itemView);
+        mHeaderHeight = mHeaderContainer.getHeight();
+        headerViewBinder.bindView(adapter, viewHolder, position, entity);
     }
 
-    public void clearHeaderView() {
+    private void clearHeaderView() {
         mHeaderContainer.removeAllViews();
     }
 

diff --git a/app/src/main/java/tellh/com/recyclerstickyheaderview/User.java b/app/src/main/java/tellh/com/recyclerstickyheaderview/User.java
@@ -4,6 +4,16 @@ public class User extends DataBean {
     private String login;
     private int id;
     private String avatar_url;
+    private boolean shouldSticky;
+
+    public User() {
+    }
+
+    public User(String login, int id, String avatar_url) {
+        this.login = login;
+        this.id = id;
+        this.avatar_url = avatar_url;
+    }
 
     public String getAvatar_url() {
         return avatar_url;
@@ -34,11 +44,13 @@ public int getItemLayoutId(StickyHeaderViewAdapter adapter) {
         return R.layout.item_user;
     }
 
+    public void setShouldSticky(boolean shouldSticky) {
+        this.shouldSticky = shouldSticky;
+    }
+
     @Override
     protected boolean shouldSticky() {
-        if (id == 1269143)
-            return true;
-        return super.shouldSticky();
+        return shouldSticky;
     }
 
     public static String dataSource = "{\"items\": [\n" +

diff --git a/app/src/main/res/layout/header.xml b/app/src/main/res/layout/header.xml
@@ -11,5 +11,5 @@
         android:layout_height="wrap_content"
         android:gravity="center"
         tools:text="H"
-        android:textSize="20sp" />
+        android:textSize="26sp" />
 </FrameLayout>
diff --git a/app/src/main/res/layout/item_user.xml b/app/src/main/res/layout/item_user.xml
@@ -16,8 +16,8 @@
 
     <ImageView
         android:id="@+id/iv_avatar"
-        android:layout_width="30dp"
-        android:layout_height="30dp"
+        android:layout_width="50dp"
+        android:layout_height="50dp"
         android:layout_gravity="center"
         tools:src="@mipmap/ic_launcher" />
 

diff --git a/app/src/main/res/menu/menu_main.xml b/app/src/main/res/menu/menu_main.xml
@@ -1,9 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<menu xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <item android:title="Add view"
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:title="Add Sticky view"
         android:id="@+id/action_add_view" />
-    <item android:title="Remove view"
-        android:id="@+id/action_remove_view" />
 </menu>